This document provides background information on the rock music genre, including its origins in the late 1940s and 1950s and evolution through subsequent decades. It lists popular rock bands and artists from the 1950s through 1990s. The genre saw mainstream success in the 1960s led by bands like The Beatles and The Rolling Stones. Rock music diversified in the 1970s with the rise of genres like heavy metal and continued to change in the 1980s-90s with new styles and digital distribution.